There is a hard limit of 300 users in the Business plans and there is no way around it. However, if you do need to go above this restriction, it is possible to upgrade to Enterprise plans where there is no user restriction. Switching plans is easy and can be done at any time using the Switch plan wizard available from the Office 365 portal.

Unlike the Enterprise plans, Office 365 Business does not allow for the addition of a mailbox archive on top of the existing 50 GB mailbox. What is possible however is to segment the existing mailbox into an archive area (for example, 5 GB of your 50 GB). It is also worth noting that this archive folder is only available when online with Outlook or via Outlook Web App because it is not cached as part of the user's Offline Storage Table (OST) file, and so it cannot be viewed offline.

If you currently utilize Office Professional in your organization, it is worth noting that none of the Business plans include the use of Microsoft Access. If some users require the use of Microsoft Access, you will need to assign an Enterprise E3, E5, or Office Pro Plus license to those users.

If your business wants to make the most of cloud technology then you will want to consider moving your on-premises telephone system to a cloud-based solution. None of the Office 365 business packages include Skype for Business Cloud PBX, which allows the users to make and receive telephone calls using Skype for Business.

If you are using Remote Desktop Services (RDS) within your organization, you will want to install the available Office applications which come with your business subscription. Unfortunately, none of the business level subscriptions include the rights to use shared computer activation, which is required to install Office on RDS servers.